This study explored the impact of infant temperament and maternal stress on the development of the infant medial prefrontal cortex (mPFC) among sixteen 6-8-month-old infants. Functional Near Infrared Spectroscopy (fNIRS) was used to measure activation of the infant mPFC in response to angry, happy, and sad faces. Infant temperament and dimensions of maternal stress were measured with the Infant Behavior Questionnaire and the Parenting Stress Index Respectively. Infants with high negative emotionality demonstrated increased mPFC activation in association with all emotion face conditions. Negative emotionality moderated the effect of total maternal stress on mPFC activation to angry and sad faces. Mother-infant dysfunctional interaction was related to increased mPFC activation associated with happy faces, supporting the “novelty hypothesis”, in which the mPFC responds more strongly to unique experiences. Therefore, this study provides additional evidence that infant temperament and the quality of the mother-infant relationship influence the development of the mPFC and how infants process emotions.

这项研究探讨了16个6-8个月大婴儿的婴儿气质和母亲压力对婴儿内侧前额叶皮层（mPFC）发育的影响。功能近红外光谱法（fNIRS）用于测量婴儿mPFC对生气，高兴和悲伤的面孔的反应。分别通过《婴儿行为调查表》和《父母压力指数》测量了婴儿的气质和产妇的压力。负情绪高的婴儿表现出与所有情绪面孔状况相关的mPFC激活增加。负性情绪减轻了母性总压力对生气和悲伤面孔对mPFC活化的影响。母婴机能障碍互动与增加与笑脸相关的mPFC激活有关，支持“新颖性假设”，其中mPFC对独特体验的反应更加强烈。因此，这项研究提供了其他证据，表明婴儿的气质和母婴关系的质量会影响mPFC的发育以及婴儿如何处理情绪。